Mercury 100 FourStroke, Service Manual

Page: 258 / 574

4-46 - POWERHEAD 90-830234R3 DECEMBER 1997
Temperature Switch Test
190
°
F (88
°
C)
The 190
°
F (88
°
C) temperature switch is located in
outer side of cylinder head as shown.
3 Cylinder Models
a
4 Cylinder Models
a
a - Temperature Switch
During normal engine operating temperature, the
switch electrical circuit is open. The switch will close
when the temperature reaches 190
°
F
±
8
°
F (88
°
C
±
4
°
C). Reset of the switch to open circuit occurs at
170
°
F
±
8
°
F (77
°
C
±
4
°
C).
To test, place switch end into water with thermometer
and heat to 190
°
F
±
8
°
F (88
°
C
±
4
°
C). Take out and
perform ohms test. Compare to specifications. If
switch does not fall within specifications, replace
switch.
Reed Blocks
NOTE: Do not disassemble reed block unless neces-
sary. It may be necessary to apply heat to bolt to soft-
en Loctite
R
before removal.
a
b
c
d
e
19331
a - Reed Block
b - Reed (3 Sets)
c - Retaining Washer
d - Tab Washer
e - Bolt
IMPORTANT: Do not “flop” (reverse) the reed for
additional use - replace reed when necessary.
BACKSIDE - REED BLOCK ASSEMBLED
19332
There are 3 reed segments. Reed should lie flat.
There should be no preload (pressure between reed
and reed-block), but a slight preload is tolerable.
The maximum allowable opening between reed and
reed-block is 0.020 in. (0.51mm). This must be
checked with a flat blade feeler gauge, as shown.